dataset test

1.practice

寫一個函數,要知道我們要的資料是不是已經內建 例如:iris是不是內建資料 function isDsExists(dsname) return T,F

常用分析物件的指令 typeof, class, str, attributes

dn<-data()
str(dn)

## List of 4
##  $ title  : chr "Data sets"
##  $ header : NULL
##  $ results: chr [1:104, 1:4] "datasets" "datasets" "datasets" "datasets" ...
##   ..- attr(*, "dimnames")=List of 2
##   .. ..$ : NULL
##   .. ..$ : chr [1:4] "Package" "LibPath" "Item" "Title"
##  $ footer : chr "Use 'data(package = .packages(all.available = TRUE))'\nto list the data sets in all *available* packages."
##  - attr(*, "class")= chr "packageIQR"

attributes(dn)

## $names
## [1] "title"   "header"  "results" "footer" 
## 
## $class
## [1] "packageIQR"

dn$results

##        Package    LibPath                             
##   [1,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [2,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [3,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [4,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [5,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [6,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [7,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [8,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##   [9,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [10,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [11,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [12,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [13,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [14,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [15,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [16,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [17,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [18,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [19,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [20,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [21,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [22,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [23,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [24,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [25,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [26,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [27,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [28,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [29,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [30,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [31,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [32,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [33,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [34,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [35,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [36,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [37,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [38,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [39,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [40,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [41,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [42,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [43,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [44,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [45,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [46,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [47,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [48,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [49,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [50,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [51,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [52,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [53,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [54,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [55,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [56,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [57,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [58,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [59,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [60,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [61,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [62,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [63,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [64,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [65,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [66,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [67,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [68,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [69,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [70,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [71,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [72,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [73,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [74,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [75,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [76,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [77,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [78,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [79,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [80,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [81,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [82,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [83,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [84,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [85,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [86,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [87,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [88,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [89,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [90,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [91,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [92,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [93,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [94,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [95,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [96,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [97,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [98,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##  [99,] "datasets" "C:/Program Files/R/R-3.5.1/library"
## [100,] "datasets" "C:/Program Files/R/R-3.5.1/library"
## [101,] "datasets" "C:/Program Files/R/R-3.5.1/library"
## [102,] "datasets" "C:/Program Files/R/R-3.5.1/library"
## [103,] "datasets" "C:/Program Files/R/R-3.5.1/library"
## [104,] "datasets" "C:/Program Files/R/R-3.5.1/library"
##        Item                    
##   [1,] "AirPassengers"         
##   [2,] "BJsales"               
##   [3,] "BJsales.lead (BJsales)"
##   [4,] "BOD"                   
##   [5,] "CO2"                   
##   [6,] "ChickWeight"           
##   [7,] "DNase"                 
##   [8,] "EuStockMarkets"        
##   [9,] "Formaldehyde"          
##  [10,] "HairEyeColor"          
##  [11,] "Harman23.cor"          
##  [12,] "Harman74.cor"          
##  [13,] "Indometh"              
##  [14,] "InsectSprays"          
##  [15,] "JohnsonJohnson"        
##  [16,] "LakeHuron"             
##  [17,] "LifeCycleSavings"      
##  [18,] "Loblolly"              
##  [19,] "Nile"                  
##  [20,] "Orange"                
##  [21,] "OrchardSprays"         
##  [22,] "PlantGrowth"           
##  [23,] "Puromycin"             
##  [24,] "Seatbelts"             
##  [25,] "Theoph"                
##  [26,] "Titanic"               
##  [27,] "ToothGrowth"           
##  [28,] "UCBAdmissions"         
##  [29,] "UKDriverDeaths"        
##  [30,] "UKgas"                 
##  [31,] "USAccDeaths"           
##  [32,] "USArrests"             
##  [33,] "USJudgeRatings"        
##  [34,] "USPersonalExpenditure" 
##  [35,] "UScitiesD"             
##  [36,] "VADeaths"              
##  [37,] "WWWusage"              
##  [38,] "WorldPhones"           
##  [39,] "ability.cov"           
##  [40,] "airmiles"              
##  [41,] "airquality"            
##  [42,] "anscombe"              
##  [43,] "attenu"                
##  [44,] "attitude"              
##  [45,] "austres"               
##  [46,] "beaver1 (beavers)"     
##  [47,] "beaver2 (beavers)"     
##  [48,] "cars"                  
##  [49,] "chickwts"              
##  [50,] "co2"                   
##  [51,] "crimtab"               
##  [52,] "discoveries"           
##  [53,] "esoph"                 
##  [54,] "euro"                  
##  [55,] "euro.cross (euro)"     
##  [56,] "eurodist"              
##  [57,] "faithful"              
##  [58,] "fdeaths (UKLungDeaths)"
##  [59,] "freeny"                
##  [60,] "freeny.x (freeny)"     
##  [61,] "freeny.y (freeny)"     
##  [62,] "infert"                
##  [63,] "iris"                  
##  [64,] "iris3"                 
##  [65,] "islands"               
##  [66,] "ldeaths (UKLungDeaths)"
##  [67,] "lh"                    
##  [68,] "longley"               
##  [69,] "lynx"                  
##  [70,] "mdeaths (UKLungDeaths)"
##  [71,] "morley"                
##  [72,] "mtcars"                
##  [73,] "nhtemp"                
##  [74,] "nottem"                
##  [75,] "npk"                   
##  [76,] "occupationalStatus"    
##  [77,] "precip"                
##  [78,] "presidents"            
##  [79,] "pressure"              
##  [80,] "quakes"                
##  [81,] "randu"                 
##  [82,] "rivers"                
##  [83,] "rock"                  
##  [84,] "sleep"                 
##  [85,] "stack.loss (stackloss)"
##  [86,] "stack.x (stackloss)"   
##  [87,] "stackloss"             
##  [88,] "state.abb (state)"     
##  [89,] "state.area (state)"    
##  [90,] "state.center (state)"  
##  [91,] "state.division (state)"
##  [92,] "state.name (state)"    
##  [93,] "state.region (state)"  
##  [94,] "state.x77 (state)"     
##  [95,] "sunspot.month"         
##  [96,] "sunspot.year"          
##  [97,] "sunspots"              
##  [98,] "swiss"                 
##  [99,] "treering"              
## [100,] "trees"                 
## [101,] "uspop"                 
## [102,] "volcano"               
## [103,] "warpbreaks"            
## [104,] "women"                 
##        Title                                                            
##   [1,] "Monthly Airline Passenger Numbers 1949-1960"                    
##   [2,] "Sales Data with Leading Indicator"                              
##   [3,] "Sales Data with Leading Indicator"                              
##   [4,] "Biochemical Oxygen Demand"                                      
##   [5,] "Carbon Dioxide Uptake in Grass Plants"                          
##   [6,] "Weight versus age of chicks on different diets"                 
##   [7,] "Elisa assay of DNase"                                           
##   [8,] "Daily Closing Prices of Major European Stock Indices, 1991-1998"
##   [9,] "Determination of Formaldehyde"                                  
##  [10,] "Hair and Eye Color of Statistics Students"                      
##  [11,] "Harman Example 2.3"                                             
##  [12,] "Harman Example 7.4"                                             
##  [13,] "Pharmacokinetics of Indomethacin"                               
##  [14,] "Effectiveness of Insect Sprays"                                 
##  [15,] "Quarterly Earnings per Johnson & Johnson Share"                 
##  [16,] "Level of Lake Huron 1875-1972"                                  
##  [17,] "Intercountry Life-Cycle Savings Data"                           
##  [18,] "Growth of Loblolly pine trees"                                  
##  [19,] "Flow of the River Nile"                                         
##  [20,] "Growth of Orange Trees"                                         
##  [21,] "Potency of Orchard Sprays"                                      
##  [22,] "Results from an Experiment on Plant Growth"                     
##  [23,] "Reaction Velocity of an Enzymatic Reaction"                     
##  [24,] "Road Casualties in Great Britain 1969-84"                       
##  [25,] "Pharmacokinetics of Theophylline"                               
##  [26,] "Survival of passengers on the Titanic"                          
##  [27,] "The Effect of Vitamin C on Tooth Growth in Guinea Pigs"         
##  [28,] "Student Admissions at UC Berkeley"                              
##  [29,] "Road Casualties in Great Britain 1969-84"                       
##  [30,] "UK Quarterly Gas Consumption"                                   
##  [31,] "Accidental Deaths in the US 1973-1978"                          
##  [32,] "Violent Crime Rates by US State"                                
##  [33,] "Lawyers' Ratings of State Judges in the US Superior Court"      
##  [34,] "Personal Expenditure Data"                                      
##  [35,] "Distances Between European Cities and Between US Cities"        
##  [36,] "Death Rates in Virginia (1940)"                                 
##  [37,] "Internet Usage per Minute"                                      
##  [38,] "The World's Telephones"                                         
##  [39,] "Ability and Intelligence Tests"                                 
##  [40,] "Passenger Miles on Commercial US Airlines, 1937-1960"           
##  [41,] "New York Air Quality Measurements"                              
##  [42,] "Anscombe's Quartet of 'Identical' Simple Linear Regressions"    
##  [43,] "The Joyner-Boore Attenuation Data"                              
##  [44,] "The Chatterjee-Price Attitude Data"                             
##  [45,] "Quarterly Time Series of the Number of Australian Residents"    
##  [46,] "Body Temperature Series of Two Beavers"                         
##  [47,] "Body Temperature Series of Two Beavers"                         
##  [48,] "Speed and Stopping Distances of Cars"                           
##  [49,] "Chicken Weights by Feed Type"                                   
##  [50,] "Mauna Loa Atmospheric CO2 Concentration"                        
##  [51,] "Student's 3000 Criminals Data"                                  
##  [52,] "Yearly Numbers of Important Discoveries"                        
##  [53,] "Smoking, Alcohol and (O)esophageal Cancer"                      
##  [54,] "Conversion Rates of Euro Currencies"                            
##  [55,] "Conversion Rates of Euro Currencies"                            
##  [56,] "Distances Between European Cities and Between US Cities"        
##  [57,] "Old Faithful Geyser Data"                                       
##  [58,] "Monthly Deaths from Lung Diseases in the UK"                    
##  [59,] "Freeny's Revenue Data"                                          
##  [60,] "Freeny's Revenue Data"                                          
##  [61,] "Freeny's Revenue Data"                                          
##  [62,] "Infertility after Spontaneous and Induced Abortion"             
##  [63,] "Edgar Anderson's Iris Data"                                     
##  [64,] "Edgar Anderson's Iris Data"                                     
##  [65,] "Areas of the World's Major Landmasses"                          
##  [66,] "Monthly Deaths from Lung Diseases in the UK"                    
##  [67,] "Luteinizing Hormone in Blood Samples"                           
##  [68,] "Longley's Economic Regression Data"                             
##  [69,] "Annual Canadian Lynx trappings 1821-1934"                       
##  [70,] "Monthly Deaths from Lung Diseases in the UK"                    
##  [71,] "Michelson Speed of Light Data"                                  
##  [72,] "Motor Trend Car Road Tests"                                     
##  [73,] "Average Yearly Temperatures in New Haven"                       
##  [74,] "Average Monthly Temperatures at Nottingham, 1920-1939"          
##  [75,] "Classical N, P, K Factorial Experiment"                         
##  [76,] "Occupational Status of Fathers and their Sons"                  
##  [77,] "Annual Precipitation in US Cities"                              
##  [78,] "Quarterly Approval Ratings of US Presidents"                    
##  [79,] "Vapor Pressure of Mercury as a Function of Temperature"         
##  [80,] "Locations of Earthquakes off Fiji"                              
##  [81,] "Random Numbers from Congruential Generator RANDU"               
##  [82,] "Lengths of Major North American Rivers"                         
##  [83,] "Measurements on Petroleum Rock Samples"                         
##  [84,] "Student's Sleep Data"                                           
##  [85,] "Brownlee's Stack Loss Plant Data"                               
##  [86,] "Brownlee's Stack Loss Plant Data"                               
##  [87,] "Brownlee's Stack Loss Plant Data"                               
##  [88,] "US State Facts and Figures"                                     
##  [89,] "US State Facts and Figures"                                     
##  [90,] "US State Facts and Figures"                                     
##  [91,] "US State Facts and Figures"                                     
##  [92,] "US State Facts and Figures"                                     
##  [93,] "US State Facts and Figures"                                     
##  [94,] "US State Facts and Figures"                                     
##  [95,] "Monthly Sunspot Data, from 1749 to \"Present\""                 
##  [96,] "Yearly Sunspot Data, 1700-1988"                                 
##  [97,] "Monthly Sunspot Numbers, 1749-1983"                             
##  [98,] "Swiss Fertility and Socioeconomic Indicators (1888) Data"       
##  [99,] "Yearly Treering Data, -6000-1979"                               
## [100,] "Girth, Height and Volume for Black Cherry Trees"                
## [101,] "Populations Recorded by the US Census"                          
## [102,] "Topographic Information on Auckland's Maunga Whau Volcano"      
## [103,] "The Number of Breaks in Yarn during Weaving"                    
## [104,] "Average Heights and Weights for American Women"

class(dn$results)

## [1] "matrix"

dimnames(dn$results)

## [[1]]
## NULL
## 
## [[2]]
## [1] "Package" "LibPath" "Item"    "Title"

class(dn$results)

## [1] "matrix"

dsname<-dn$results[,"Item"] # 亦可dsname<-dn$results[,3]
head(dsname,10)

##  [1] "AirPassengers"          "BJsales"               
##  [3] "BJsales.lead (BJsales)" "BOD"                   
##  [5] "CO2"                    "ChickWeight"           
##  [7] "DNase"                  "EuStockMarkets"        
##  [9] "Formaldehyde"           "HairEyeColor"

note

要知道前10筆資料為哪些:head(xxx,10) PS.全列就直接打head(xxx) 要知道後10筆資料為哪些:tail(xxx,10) PS.全列就直接打tail(xxx)

oo<-dn$results
oo[,3]

##   [1] "AirPassengers"          "BJsales"               
##   [3] "BJsales.lead (BJsales)" "BOD"                   
##   [5] "CO2"                    "ChickWeight"           
##   [7] "DNase"                  "EuStockMarkets"        
##   [9] "Formaldehyde"           "HairEyeColor"          
##  [11] "Harman23.cor"           "Harman74.cor"          
##  [13] "Indometh"               "InsectSprays"          
##  [15] "JohnsonJohnson"         "LakeHuron"             
##  [17] "LifeCycleSavings"       "Loblolly"              
##  [19] "Nile"                   "Orange"                
##  [21] "OrchardSprays"          "PlantGrowth"           
##  [23] "Puromycin"              "Seatbelts"             
##  [25] "Theoph"                 "Titanic"               
##  [27] "ToothGrowth"            "UCBAdmissions"         
##  [29] "UKDriverDeaths"         "UKgas"                 
##  [31] "USAccDeaths"            "USArrests"             
##  [33] "USJudgeRatings"         "USPersonalExpenditure" 
##  [35] "UScitiesD"              "VADeaths"              
##  [37] "WWWusage"               "WorldPhones"           
##  [39] "ability.cov"            "airmiles"              
##  [41] "airquality"             "anscombe"              
##  [43] "attenu"                 "attitude"              
##  [45] "austres"                "beaver1 (beavers)"     
##  [47] "beaver2 (beavers)"      "cars"                  
##  [49] "chickwts"               "co2"                   
##  [51] "crimtab"                "discoveries"           
##  [53] "esoph"                  "euro"                  
##  [55] "euro.cross (euro)"      "eurodist"              
##  [57] "faithful"               "fdeaths (UKLungDeaths)"
##  [59] "freeny"                 "freeny.x (freeny)"     
##  [61] "freeny.y (freeny)"      "infert"                
##  [63] "iris"                   "iris3"                 
##  [65] "islands"                "ldeaths (UKLungDeaths)"
##  [67] "lh"                     "longley"               
##  [69] "lynx"                   "mdeaths (UKLungDeaths)"
##  [71] "morley"                 "mtcars"                
##  [73] "nhtemp"                 "nottem"                
##  [75] "npk"                    "occupationalStatus"    
##  [77] "precip"                 "presidents"            
##  [79] "pressure"               "quakes"                
##  [81] "randu"                  "rivers"                
##  [83] "rock"                   "sleep"                 
##  [85] "stack.loss (stackloss)" "stack.x (stackloss)"   
##  [87] "stackloss"              "state.abb (state)"     
##  [89] "state.area (state)"     "state.center (state)"  
##  [91] "state.division (state)" "state.name (state)"    
##  [93] "state.region (state)"   "state.x77 (state)"     
##  [95] "sunspot.month"          "sunspot.year"          
##  [97] "sunspots"               "swiss"                 
##  [99] "treering"               "trees"                 
## [101] "uspop"                  "volcano"               
## [103] "warpbreaks"             "women"

not in function(prior function)

head(dsname,10)

##  [1] "AirPassengers"          "BJsales"               
##  [3] "BJsales.lead (BJsales)" "BOD"                   
##  [5] "CO2"                    "ChickWeight"           
##  [7] "DNase"                  "EuStockMarkets"        
##  [9] "Formaldehyde"           "HairEyeColor"

uname<-"BOD"
dsname==uname

##   [1] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [12] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [23] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [34] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [45] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [56] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [67] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [78] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [89] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [100] FALSE FALSE FALSE FALSE FALSE

length(dsname[dsname==uname])

## [1] 1

length(dsname[dsname=="xxx"])

## [1] 0

#解一
isDsExists<-function(given){
  dn<-data()
  dsname<-dn$results[,"Item"] # 亦可dsname<-dn$results[,3]
  rst<-length(dsname[dsname==given])
  if(rst!=0){
    return(TRUE)
  }
  else{
    return(FALSE)
  }
}

isDsExists("iris")

## [1] TRUE

isDsExists("BOD")

## [1] TRUE

isDsExists("xxx")

## [1] FALSE

#解二
isDsExists2<-function(given){
  dn<-data()
  dsname<-dn$results[,"Item"] # 亦可dsname<-dn$results[,3]
  return(any(dsname==given))

}
isDsExists("iris")

## [1] TRUE

isDsExists("BOD")

## [1] TRUE

isDsExists("xxx")

## [1] FALSE

最後將isDsExists做成程式包:

1. 先建立記事本
2. 右鍵點Edit with Noptepad++,將下方語法貼入即可 isDsExists<-function(given){ dn<-data() dsname<-dn\(results[,"Item"] # 亦可dsname<-dn\)results[,3] rst<-length(dsname[dsname==given]) if(rst!=0){ return(TRUE) } else{ return(FALSE) } }
3. 存成isDsExists.R
4. 欲使用語法時,就使用source(“isDsExists.R”)喚回

2.先執行install.packages(“DT”),下載DT程式包

library(DT) # 喚醒DT程式
datatable(cars)  #將cars製作成表格

dn<-data()
dsname<-dn$results[,3]
df<-data.frame(dsname) 
# 因為dn$results[,3]為一行的數字表格,所以使用data.frame(dsname)使其變成至少兩行的表格,如此才能使用datatable語法
datatable(df)

#製作表格按鈕,可參考:https://rstudio.github.io/DT/003-tabletools-buttons.html
#google搜尋:r language datatable button
dn<-data()
dsname<-dn$results[,3]
df<-data.frame(dsname) 
datatable(df, extensions = 'Buttons', options = list(
    dom = 'Bfrtip',
    buttons = 
      list('copy', 'print', list(
        extend = 'collection',
        buttons = c('csv', 'excel', 'pdf'),
        text = 'Download'
      ))
    )
)

#不知道為何excel的選項出不來

note

要知道資料及裡面有什麼欄位:names() 要知道前10筆資料為哪些:head() 要知道後10筆資料為哪些:tail()